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Looking forward to it. 2 of the lectures are on SALRE. Always fun to watch the lights come on for people with that one.
Drink a Guinness for me while you are in the Emerald Isle!!
__________________
Sincerely,
Kevin
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Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Here's a thought, has anyone described a pronation resistance test in which the examiner places fingers or a force gauge under the cuboid and attempts to pronate the foot? Measuring load/ displacement should give a measure of pronation stiffness too. What if we measured the ratio of supination stiffness to pronation stiffness??
John Weed described placing fingers under the lateral forefoot. That is sort of a pronation resistance test and I think John Weed was looking at pronation of the long axis of the MTJ, but still usefull information. I've also described the maximum eversion height test which is sort of close in that we are looking at if pronation is resisted by the end of range of motion of the STJ and MTJ.
Coming kind of late to the thread. I'll try and sum everything up.
With STJ axis motion there is movement coupling of some other joints when weigth bearing. Specifically there is internal leg (and talar) rotation with STJ pronation. Applying a medial to lateral force at the talar head/navicular can slow this pronation. One would rightly ask why as this force is quite close to the location of the STJ axis. The correct answer, in my opinion, was pointed out that when there is a medial to lateral force there will be an acceleration unless there is an equal and opposite lateral to medial force. With a lateral to medial force at the heel and distal 5th metatarsal shaft these forces will create a supination moment at the STJ as seen in the diagram in the paper that Simon posted.
[Applying a medial to lateral force at the talar head/navicular can slow this pronation. One would rightly ask why as this force is quite close to the location of the STJ axis. The correct answer, in my opinion, was pointed out that when there is a medial to lateral force there will be an acceleration unless there is an equal and opposite lateral to medial force. With a lateral to medial force at the heel and distal 5th metatarsal shaft these forces will create a supination moment at the STJ as seen in the diagram in the paper that Simon posted.
Eric[/quote]
Dr.Fuller,
i would imagine that an equal and opposite force lateral to medial should cancel the medial - lateral force from the orthotic, and the net force would become zero.
[Applying a medial to lateral force at the talar head/navicular can slow this pronation. One would rightly ask why as this force is quite close to the location of the STJ axis. The correct answer, in my opinion, was pointed out that when there is a medial to lateral force there will be an acceleration unless there is an equal and opposite lateral to medial force. With a lateral to medial force at the heel and distal 5th metatarsal shaft these forces will create a supination moment at the STJ as seen in the diagram in the paper that Simon posted.
Eric
Dr.Fuller,
i would imagine that an equal and opposite force lateral to medial should cancel the medial - lateral force from the orthotic, and the net force would become zero.
i dont understand
David[/quote]
What I did not do was fully label my forces. That might help you. A medial to lateral force from an AFO/orthotic/UCBL applied to the talar head....
The equal and opposite force you are talking about is from the foot applied to the AFO etc....
Re: Another Axis. A 3 point model.
Linear Mode
